Blow-by gas treatment device for internal combustion engine

Abstract

A blow-by gas treatment device includes a first blow-by gas pipe, a second blow-by gas pipe, a first pipe joint located on a first head cover, the first blow-by gas pipe being connected to the first pipe joint, a second pipe joint located on a second head cover, the second blow-by gas pipe being connected to the second pipe joint, a first union located on the first pipe joint, a second union located on the second pipe joint, and a pressure sensor connected to the first pipe joint by the first union and connected to the second pipe joint by the second union.

The invention claimed is: 
     
       1. A blow-by gas treatment device comprising:
 blow-by gas pipes configured to cause blow-by gas in a space defined by a cylinder head and a head cover in an internal combustion engine to flow back into an intake pipe, the blow-by gas pipes including
 a first blow-by gas pipe connected to the intake pipe, and 
 a second blow-by gas pipe connected to a part of the intake pipe that differs from a part of the intake pipe connected to the first blow-by gas pipe; 
 
 a first pipe joint located on the head cover, wherein the first blow-by gas pipe is connected to the first pipe joint; 
 a second pipe joint located on the head cover, wherein the second blow-by gas pipe is connected to the second pipe joint; 
 a first union located on the first pipe joint, wherein an inside of the first union communicates with an inside of the first pipe joint; 
 a second union located on the second pipe joint, wherein an inside of the second union communicates with an inside of the second pipe joint; and 
 a pressure sensor connected to the first pipe joint by the first union and connected to the second pipe joint by the second union; 
 a first connection pipe extending from the pressure sensor to the first union; and 
 a second connection pipe extending from the pressure sensor to the second union. 
 
     
     
       2. The blow-by gas treatment device according to  claim 1 , wherein
 the internal combustion engine includes a first bank and a second bank, 
 the cylinder head is one of a first cylinder head corresponding to the first bank and a second cylinder head corresponding to the second bank, 
 the head cover is one of a first head cover attached to the first cylinder head and a second head cover attached to the second cylinder head, 
 the first pipe joint is located on the first head cover, and 
 the second pipe joint is located on the second head cover. 
 
     
     
       3. The blow-by gas treatment device according to  claim 1 , wherein each of the first pipe joint and the second pipe joint includes a basal end connected to the head cover and a constriction located closer to the basal end than the corresponding one of the first union and the second union. 
     
     
       4. The blow-by gas treatment device according to  claim 1 , wherein each of the first pipe joint and the second pipe joint includes a basal end connected to the head cover and a constriction located between the basal end and the corresponding one of the first union and the second union.